Is the VNT moving? Possibly disconnected?
Loose boost hose/coupling?
Did they change the DPF? The oil from a blown turbo would have plugged it up. If not expect to delete it or wait 4-6 months for a new DPF.
I agree that is has to do with the lift pump.
First confirm that it is running and pumping fuel.
Check the pickup tube/fuel inlet strainer for cracks. The fact this is worse below 3/4 tank seems to point that way.
I need some advice on the source of an oil leak found during an oil change.
The area around the injectors has oil on it.
The "gallery" where the bolts are have oil in then.
Oil is running down the rear of the engine/turbo.
Ideas? Cracked valve cover? Loose bolts?
If you've ever driven a vehicle with 250 gal of fuel, it's nice to be able to plan fuel stops based on price.
You can always stop more just to pee :-)
My current work takes me twice a week across state lines with nearly a $0.50 price savings. Last week I rolled in with 5 miles on the display...